Starter cultures - Catalase positive LAB

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Catalase positive LAB

Printed From: Dairy Science and Food Technology
Category: Starter cultures
Forum Name: Starter cultures
Forum Description: Discussion about the microorganisms used in the manufacture of cultured products
URL: https://www.dairyscience.info/forum/forum_posts.asp?TID=127
Printed Date: 20 Apr 2024 at 2:51am
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Topic: Catalase positive LAB

Posted By: Guests
Subject: Catalase positive LAB
Date Posted: 22 Mar 2010 at 10:43pm

Hope u can help. I have isolated several LAB that show gas production when added to H2O2-catalase positive. Is this possible? Any info appreciated. Liked the reference wizard!

Replies:

Posted By: Guests
Date Posted: 22 Mar 2010 at 10:44pm

Some lactic acid bacteria including lactobacilli, enterococci and pedococci can produce a pseudocatalase. This can result in a false positive reaction for catalase, creating problems in isolate classification. The activity of catalase is due to its haem group. Pseudocatalase does not contain a haem group but does contain manganese.

Posted By: Guests
Date Posted: 22 Mar 2010 at 10:44pm

Interesting-can u distuingish b/w the 2 catalases

Posted By: Guests
Date Posted: 22 Mar 2010 at 10:44pm

Firstly I should add that some LAB can produce a true catalase on
media containing hematin or related compounds.

I think I tried out benzidine reagent to detect pseudocatalase but this was many years ago. Google Scholar will probably yield more effective modern methods. Benzidine is fairly dangerous to work with so you may wish to find a safer chemical.